Cable laying arrangements for industrial articulated robots incorporate various devices for laying power supply cables and signal transmission cables on the industrial articulated robots. Most of these conventional cable laying arrangements for industrial robots lay cables extended through the robot base and the robot trunk directly within the robot arm unit serving as a structural element that supports loads, such as a robot wrist and an end effector as well as a functional element for robot actions.
A well-known cable laying arrangement arranges tubing, such as known conduits, on the side surface of the robot unit and runs power supply cables and signal transmission cables through the tubing to avoid laying the power supply cables and the signal transmission cables in an exposed state on the exterior of the robot unit from the view point of securing safety and avoiding spoiling the appearance of the robot unit.
Another known cable laying arrangement which avoids exposing cables runs a bundle of cables through cable bearers available on the market, such as CABLEBEAR (Trademark of Tsubakimoto Chain Co. in Japan), capable of following the swing motion and the linear motion of the robot arm, i.e., the structural element of the robot unit, and attached to the exterior and the like of the robot arm.
The known cable laying arrangement that runs the cables through the robot arm unit needs a series of very troublesome assembly operations and a lot of time, in case of failures, such as failure in supplying power or failure in transmitting signals, is needed to replace the faulty cables with new ones by pulling out the faulty cables from the robot arm and the structural elements, and to lay the new cables within the robot arm unit.
The known cable laying arrangement employing tubing needs, when the wires of the power supply cables and the signal transmission cables are provided with connectors at their opposite ends, to remove all the connectors from the wires of the cables, to draw out all the cables from the tubing and, eventually, to replace the bundle of cables with a new bundle of cables even if only a single one of the wires of one of the cables is disconnected, which costs a great deal.
The known cable laying arrangement employing cable bearers, arranging the cable bearers on the exterior of the robot unit, such as the exterior of the robot arm unit, and holding the bundle of cables within the cable bearers suffers from problems that dust and oil mists leak through gaps in the cable bearers into the cable bearers and adhere to the surface of the cables of the bundle to deteriorate the cables when the industrial robot is used in a foul atmosphere containing floating particles of dust, paint and oil, because the cable bearers are not air-tight.